C语言打印菱形

#include <stdio.h>

int main(void)
{
int n = 4;
int i, j;

for (i = 1; i <= n; i++)
{
for (j = 1; j < n - i + 1; j++)
printf(" ");
for (j = 1; j <= i; j++)
printf("%d",j);
for (j = i - 1; j >= 1; j--)
printf("%d",j);
printf("\n");
}

for (i = n - 1; i >= 1; i--)
{
for (j = 1; j < n - i + 1; j++)
printf(" ");
for (j = 1; j <= i; j++)
printf("%d",j);
for (j = i - 1; j >= 1; j--)
printf("%d",j);
printf("\n");
}
}

循环控制输入